I can understand how that would be incredibly stressful and hurtful. I really hope things do well with the new T and you're able to talk to her about it. When is your appointment?

When things ended badly with my first therapist a decade ago, she told me no other therapist would be willing to put up with me. It wasn't as painful as what you're going through because I wasn't attached to her, but I definitely believed it for a long time.

One of the things that helped was that my current T is that he's nothing like her. Different gender, different degree, different personality, different way of thinking, different dynamics, etc.

I still have that fear though. I kept warning him that I could be "too much" and asking if he was sure he was willing to work with me. I emphasized that if he wasn't sure I'd really rather he referred me out at the beginning, rather than giving it a try and then deciding he couldn't work with me.
It's only been 3-4 months, but last session I told him all the absolute worst stuff that I thought might make him terminate, and told him I'd understand if he did but to please, if he wasn't sure he could handle it, terminate now, because it would be really hard for me if we kept working together and then eventually somewhere down the line he decided he'd made a mistake, especially if he'd told me now that that wouldn't be the case and I trusted him.
He understood all of that, and didn't terminate. This week I'm planning to ask him what circumstances would make him terminate.

Trying to get the "worst" out in the beginning has helped me relax a little. It was terrifying to be wondering if he would terminate if he knew or found out these things, so I got it over with and got it all out there. Now I feel more secure knowing there aren't any secrets or surprises left on my end.

I don't know how long you saw your old T or how much they already knew from the beginning, so I'm not saying you concealed anything or that concealing something would make this your fault somehow. And obviously my T could still end up unexpectedly terminating despite his assurances so far. But these are just the things that have made me feel safer in trusting him.

I really hope things go well with your new T.